ndisc: Update neigh->updated with write lock.

neigh->nud_state and neigh->updated are under protection of
neigh->lock.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 7c34c01b515b..1341f68e8009 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -499,22 +499,26 @@ static void rt6_probe(struct rt6_info *rt)
          * to no more than one per minute.
          */
         neigh = rt ? rt->n : NULL;
-        if (!neigh || (neigh->nud_state & NUD_VALID))
+        if (!neigh)
+                return;
+        write_lock_bh(&neigh->lock);
+        if (neigh->nud_state & NUD_VALID) {
+                write_unlock_bh(&neigh->lock);
                 return;
-        read_lock_bh(&neigh->lock);
+        }
         if (!(neigh->nud_state & NUD_VALID) &&
             time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
                 struct in6_addr mcaddr;
                 struct in6_addr *target;
 
                 neigh->updated = jiffies;
-                read_unlock_bh(&neigh->lock);
+                write_unlock_bh(&neigh->lock);
 
                 target = (struct in6_addr *)&neigh->primary_key;
                 addrconf_addr_solict_mult(target, &mcaddr);
                 ndisc_send_ns(rt->dst.dev, NULL, target, &mcaddr, NULL);
         } else {
-                read_unlock_bh(&neigh->lock);
+                write_unlock_bh(&neigh->lock);
         }
 }
 #else